/* Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.activiti.engine.impl.event;

import java.util.Map;

import org.activiti.engine.ActivitiException;
import org.activiti.engine.delegate.event.impl.ActivitiEventBuilder;
import org.activiti.engine.impl.bpmn.behavior.BoundaryEventActivityBehavior;
import org.activiti.engine.impl.bpmn.behavior.EventSubProcessStartEventActivityBehavior;
import org.activiti.engine.impl.interceptor.CommandContext;
import org.activiti.engine.impl.persistence.entity.EventSubscriptionEntity;
import org.activiti.engine.impl.persistence.entity.ExecutionEntity;
import org.activiti.engine.impl.pvm.process.ActivityImpl;
import org.flowable.common.engine.impl.interceptor.EngineConfigurationConstants;
import org.flowable.engine.impl.delegate.ActivityBehavior;

/**
 * @author Daniel Meyer
 * @author Falko Menge
 */
public abstract class AbstractEventHandler implements EventHandler {

    @Override
    public void handleEvent(EventSubscriptionEntity eventSubscription, Object payload, CommandContext commandContext) {

        ExecutionEntity execution = eventSubscription.getExecution();
        ActivityImpl activity = eventSubscription.getActivity();

        if (activity == null) {
            throw new ActivitiException("Error while sending signal for event subscription '" + eventSubscription.getId() + "': "
                    + "no activity associated with event subscription. Hint: The activityId of this event should be present in the BPMN.");
        }

        if (payload instanceof Map) {
            @SuppressWarnings("unchecked")
            Map<String, Object> processVariables = (Map<String, Object>) payload;
            execution.setVariables(processVariables);
        }

        ActivityBehavior activityBehavior = activity.getActivityBehavior();
        if (activityBehavior instanceof BoundaryEventActivityBehavior
                || activityBehavior instanceof EventSubProcessStartEventActivityBehavior) {

            try {

                dispatchActivitiesCanceledIfNeeded(eventSubscription, execution, activity, commandContext);

                activityBehavior.execute(execution);

            } catch (RuntimeException e) {
                throw e;
            } catch (Exception e) {
                throw new ActivitiException("exception while sending signal for event subscription '" + eventSubscription + "':" + e.getMessage(), e);
            }

        } else { // not boundary
            if (!activity.equals(execution.getActivity())) {
                execution.setActivity(activity);
            }
            execution.signal(eventSubscription.getEventName(), payload);
        }
    }

    protected void dispatchActivitiesCanceledIfNeeded(EventSubscriptionEntity eventSubscription, ExecutionEntity execution, ActivityImpl boundaryEventActivity, CommandContext commandContext) {
        ActivityBehavior boundaryActivityBehavior = boundaryEventActivity.getActivityBehavior();
        if (boundaryActivityBehavior instanceof BoundaryEventActivityBehavior) {
            BoundaryEventActivityBehavior boundaryEventActivityBehavior = (BoundaryEventActivityBehavior) boundaryActivityBehavior;
            if (boundaryEventActivityBehavior.isInterrupting()) {
                dispatchExecutionCancelled(eventSubscription, execution, commandContext);
            }
        }
    }

    protected void dispatchExecutionCancelled(EventSubscriptionEntity eventSubscription, ExecutionEntity execution, CommandContext commandContext) {
        // subprocesses
        for (ExecutionEntity subExecution : execution.getExecutions()) {
            dispatchExecutionCancelled(eventSubscription, subExecution, commandContext);
        }

        // call activities
        ExecutionEntity subProcessInstance = commandContext.getExecutionEntityManager().findSubProcessInstanceBySuperExecutionId(execution.getId());
        if (subProcessInstance != null) {
            dispatchExecutionCancelled(eventSubscription, subProcessInstance, commandContext);
        }

        // activity with message/signal boundary events
        ActivityImpl activity = execution.getActivity();
        if (activity != null && activity.getActivityBehavior() != null) {
            dispatchActivityCancelled(eventSubscription, execution, activity, commandContext);
        }
    }

    protected void dispatchActivityCancelled(EventSubscriptionEntity eventSubscription, ExecutionEntity execution, ActivityImpl activity, CommandContext commandContext) {
        commandContext.getEventDispatcher().dispatchEvent(
                ActivitiEventBuilder.createActivityCancelledEvent(activity.getId(),
                        (String) activity.getProperties().get("name"),
                        execution.getId(),
                        execution.getProcessInstanceId(), execution.getProcessDefinitionId(),
                        (String) activity.getProperties().get("type"),
                        activity.getActivityBehavior().getClass().getCanonicalName(),
                        eventSubscription),
                EngineConfigurationConstants.KEY_PROCESS_ENGINE_CONFIG);
    }

}
